2 year old, fever, white bumps on back throat, vomitting, mouth hurts, tongue red/taste buds swollen. Asks for water. What could this be? Been 2 doc.

Viral illness. Making him feel comfortable by giving him antipyretic such as tylenol (acetaminophen) and encouraging fluid intake would be all he needs. Be patient, viral illness generally runs a few days.
See your MD. Could be strep but if not primary herpetic stomatitis, apthous stomatitis, coxackie virus all have similar presentations. Because they are viral in nature, there is not much to do besides wait them out, attempt to help the symptoms with childrens motirn/tylenol following the instructions on the bottle, and make sure your child does not dehydrate. Pedialyte/pediasure can help replenish fluids.